Instructables

How high should a rain barrel be to develop good pressure? Is there a formula?


kevinhannan3 years ago
What i have done years ago is plastic-weld three water barrels on top of each other to form one huge but tall barrel- the outlet being the one at the bottom.

As the barrel is full the pressure is greatest and as it depletes the pressure becomes less.

Weight was not a problem as it was on a concrete floor and the barrels were strapped securely to the garage.

To increase the force of water I took some copper tubing and squashed one end flat but not entirely closed (paper thickness). The other end I used a worm-screw/jubilee clip to secure the copper pipe to the hosepipe.

orksecurity3 years ago
How much pressure do you really need?

My solution is low-pressure drip irrigation.

My neighbor's solution was to elevate the barrels about 4 feet above the highest point on their property (remember that the platform has to carry a lot of weight -- a pint's a pound, so a full 55-gallon drum is around 450 pounds -- so this is not a place to take shortcuts). I don't know how much pressure that actually gives them, but it seems to be enough for their purposes.

Another common solution is to just buy a suitable pump.
In SI units
Pressure in Pascal = Height of water surface in barrel x density of water x g
= height x 1000 x 10
Convert Pa to Bar x 10^-5

Pressure in Bar = height in metres / 10 !!